Method and apparatus for obtaining work from vapor.



1. G. PRoSsER.

APPLICATION FILED APR. 22. T915.

Patented Dec. 28, 1915.

dil

JOSEPH G. PROSSER, OF CHXCAGU, LLNOS.

METHOD .AND APPARATUS FR OBTAINING WORK FROM VAPOR.

Specification oi" Letters Eatent.

Patented Dec. 28, imei..

Continuation of application Serial No. "684,396, filed lli'arch i8, 1912. This application filed April 22, 1915.

Serial No. 23353.

To all whom t may concern.'

Be it known that l, JOSEPH G. Prossnn, a subject of the King of Great Britain, residing at Chicago, county of Cook, State of Illinois, have invented an improvement in Methods and Apparatus for Obtaining Work from Vapor, of which the'following description, in connection with the accompanying drawing, is a specication, like characters or. the drawing representing like parts.

This invention involves a method and apparatus 'for obtainin work from vapor.' The broad principles involved are applicable to various vapors under suitable conditions.

The invention involves in the particular form illustrated and more specifically described herein the use of steam or water vapor and the improvement or in fact the reorganization of the steam engine, whereby the eiliciency of a single cylinder engine can,`

ne' increased to the maximumpossible in the cycle. llhe smaller slzes may be .caused thereby to equal or exceed in eciency thev multiple cylinder engines of the present, although the principles involved can also be applied to multi-cylinder engines with advantage, especially when reheaters are used between the cylinders.

It has from the .iirst been realized kthat the amount oi' work obtained from the piston in a steam engine was butia comparatively sinall traction of that represented by the steam admitted tothe cylinder.` Ever since the days oi'VVatt continuous eort has been made togeliminate as much of this loss as possiblefilVariWs methods have been' devised, used or suggested for this purpose,

including the j'acl'etmglzof the cylinder and even of the pistoftlieuse of superhe'ated steam, and""other expediente familiar to the engineer and student of thermodynamics, but, owing to the' failure to understand the necessity of pro erly correlating. these and other structura characteristics4 a'e'cting thermal conditions and other thermal conditicns with the speed of the pistoni andthe volume of vapor admitted, full advantage has been vtaken of none. Hencevthe determination ofthe design 'and work' performf ance of the engine have never been the product of exact.- scientific principles but rather onlv of experiment. i y

The resent invention provides a method for the vandling of the vapor, such as steam,

and an apparatus embodying the method, whereby new principles are developed and made use of and a radical saving is effected.

While the steam engine as an energy transforming device is very familiar and has been made a subject of endless investigation and discussion, yet itv involves the investigation and application of thermodynamic theories abstruse in'their nature and not thoroughly demonstrated. ln disclosing this invention it will be impossible therefore to define with theoretical accuracy and in tech nical terms the principles here involved. Theobject will be to set forth as fully as possible the method and means by which the new results are secured. IThe theories propounded 'are for the purpose of illustrating or illuminating the disclosure, and not for the purpose of limiting or restricting. The inventor has ldiscovered certain new .principles which may be readily applied by anyone skilled inthe art and by which the desired results may be secured.-A rlhe basic principle thus discovered is that of the cor relation between the volume of the vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the thermal conditions, and the speed of the piston to insure that the vapor at the end of the expansion shall be in a substantially saturated condition. 'lhe prevention of initial condensation is secured by this correlation and the condition of the vapor at the end of the expansion is selected as a criterion for ascertaining this condition because `it is one which is readily available. .With

the vapor at the end of the expansion in an exact saturated condition a slightyariation 0f the quality has no substantial eect upon the efiiclency of the'engine but such a variation permits a Wide range of capacity. F or this reason the'correlation of this invention may best be defined as insuring substantially saturated vapor at the end of the expansion.

'llhe conditions existing within the engine cylinder and the principles governing the resent invention may be better understood y adopting a theory in regard to heat, al-

though the benefits tobe derived from this `invention do not depend upon the truth of .the theory. The theoretical ropositions herein advanced are not assumed to be complete or conclusive, but are rather illustrative and explanatory. llt may be assumed that heat isa inode of motion and of separation among the molecules or some portion or portions of these molecules of whlch matter is formed, whether it be the metal of' which exists between every two masses of whatever size. 'At the same time the molecules tend to separate -from each other under the influence of the centrifugal force developed by the tangential action of the molecules in their orbits.

In the case of a solid it is supposed that the molecules are moving in paths, la great majority of which are elliptical. and approaching the circular, while the diameters of these orbits are small and bear possibly some proportion to the specific gravity or the density of the solids. It is supposed that in the caseI of liquidsthe space relations between the molecules have increased, their orbits become much flattened, and the speed of the molecules in their paths increased. In the case of vapors or gases it is supposed that this increase has continued to a much greater degree than in the case of liquids, resulting 1n far wider space relationships, in far greater speed in the molecules, and in increasing eccentricity of their orbits until the vast majority' assume the form of extremely flattened ellipses or of hyperbolas. Adopting this hypothesis `for purposes' of illustration, the conditions controlling in a vapor engine will now be considered, and the steam engine will be considered specifically because of its familiar 4character and general use. The principles of the invention are readily explained in connection with the steam engine and whenl embodied therein work its radical improvement. But other types of engines such as turbines or engines operating with other vapors are considered within the scope of the invention, and under proper conditions may produce even better results.

Let the conditions in the cylinder vbe considered with the piston-standing still at the exhaust 'end of its stroke and on the assumption that the admission and exhaust valves may be opened at will, and that the exhaust valve is connected to a condenser. Assume for example that steam is supplied to the admission at a pressure of 150 pounds absolute, and that the condenser is maintained at a uniform ressure of 4 pounds absolute. If now, with t ie exhaust 'valve closed, the admission valve be opened for a short time and again closed, the steam vapor will till the cylinder. Assuming that the cylinder walls are composed of cast iron and have a temperature of 1000 F., then the molecules of the matter in the walls will have space relations and motion due to a temperature of 100 F., while the molecules of the steam vapor will have space relations and motion due to a temperature of `358.26" F. Before, therefore, the -iron and the vapor can remain in contact without any apparent change taking place in either, an equilibrium must be established between the two. The molecules of the vapor surface adjacent to the molecules of the wall surface exchange energy, the eiect being to increase the space relations and amplify the orbits in the metal, and decrease the space relations and contract the orbits in the vapor. Thosey molecules coming closest to the metal surface would be so aiected as to take the form of liquid, thus presenting the phenomenon of liquefaction. In all probability a varied exchange in heat between the vapor molecules, the liquid molecules and the ironmolecules in varying combinations takes place, until inally an equilibrium is effected. The conditions under which such an equilibrium was effected would depend upon various circumstances. The iron would have to be heated all through to the same temperature as at its surface, and this would have to be the same temperature as the vapor. Hence the specific heat and the vthickness of the walls and the length` of time that the vapor remained in the cylinder would affect the iinal result. It might be necessary to fill the cylinder with vapor several times before any vapor would.pass.A into the condenser upon opening the eX- haust valve. The operation may be repeated until conditions are such that when the vapor is admitted into the cylinder a much smaller percentage i of liquefaction takes place on the walls, even when time is taken to permit a practical balance throughout the system to be obtained.

Further explanation may be aided by the use of specific figures. Assuming that the cylinder contained three cubic feet and that one pound of vapor, or just enough to ll the cylinder, were admitted. lf 1000 grains of moisture were found adhering to the walls of the cylinder, there would be remaining in vapor about 2000 grains to the cubic foot, but this is the weight due to steam at a little over 19.8 pounds absolute pressure; -The cylinder would then be full of vapor at 128 pounds absolute and the surface coated with one-seventh of a pound of water, distributed wherever any cooling took place in the vapor. If now the exhaust valve be opened and the vapor passed into the condenser, immediatelv the equilibrium previously established is disturbed, the condensed moisture is revaporated, taking heat from the iron Walls, and the pressure in the cylinder is reduced to that of the condenser, assumed to be. four pounds absolute. will now be found that the Walls of the cylinder are Warmer than they Were When the admission valve Was opened to admit the steam to the cylinder. The reason for this may be made clear by continuing the use of specific figures as an illustration. When the one pound of steam Was admitted at 358.260 F., 1191.2 heat units were admitted into the cylinder and, on opening the exhaust, one-seventh of a pound of moisture Was evaporated at a pressure slightly less than 128 pounds absolute. It may be as* sumed that this lesser pressure Was 127 pounds absolute. This one pound of va,- por passed into the condenser When the exhaust Valve was open, carrying 1187.3 heat units, leaving the balance of 3.9 hea-t units in the cylinder Walls when the moisture Was evaporated.

rlhe admission and release of the vapor may be continued and as a result the temperature of the Walls Would slightly rise so long as only .dry vapor was admitted. The nearer the Walls approach in temperature to the steam, the slower Will be the gain, but eventually a temperature of the Walls, fairly close to that of the incoming steam, could be obtained, although it is obvious. that it v never could be reached in this manner. Let it be assumed, however, that the temperature of the Walls is in some Way brought up to the temperature of the steam When it enters the cylinder. 1f now steam be admitted, bringing with it into the cylinder a certain amount of Water entrained or otherwise, which under ordinary conditions of saturated steam will be not less than one per cent., or 'in the illustrated case seventy grains, this Water Will probably in part at least, if not entirely, adhere to t-he walls of the cylinder as it strikes the Walls. But this Water being of the same temperature as the Walls and the vapor, nothing happens until the exhaust valve to the condenser is opened. When this is done the grains of Water are immediately evaporated owing to thev reduction in pressure and practically at the high temperature of the Walls, or the evaporation takes place at a pressure slightly under 150 pounds absolute. Hence 8.6 units of heat, being the latent heat of vaporrization, are extracted from the Walls to 'evaporate this Water. Thus 8.6 heat units are transferred from the cylinder' walls tothe contents of the cylinder upon the opening of' the exhaust valve. Onvthe next filling of the cylinder enough vapor must be liquefied on the Walls to make up for the 8.6 heat units extracted, While at the same time the one per cent. or 70 more grains of Water Will be brought in, thus presenting 140 'grains to be evaporated upon the second filling of the cylinder. U'llhis liquefaction continues to increase at each filling of the cylinder until the moisture runs off any surfaces affected and then out of the exhaust port as soon as it is opened. heat that is absorbed from the admitted steam is retained in the Wall instead of being carried out in exhaust.

The time allowed for liquefaction and for revaporation from the Wall surfaces, and the ease with which Water Will drain ofi" these surfaces are the controlling elements in fixing the quantity of steam that Willpass vapor to Warm up the-Wall surfaces after these surfaces are raised to a temperature that does not necessitate liquefaction of the molecules that come into propinquity With them. Butfif the inlet valve is open but a short time liquefaction on the cool surfaces is the principal phenomenon before its closure, While if the exhaust valve is open for a long time all Water on these surfaces Will abstract heat of vaporization therefrom and thus a large quantity of vapor is carried out of the cylinder each time the exhaust opens owing to the low temperature to which the Walls are reduced and the amount of liquefaction that takes place as a result. In this case no consideration has been given to any amount of heat which would be -abstracted Thus a large amount of the.

from the hot Walls of the cylinder by the vapor While being exhausted.

The first principle upon which this invention is based is, therefore, this cumulative effect of any cooling actionin the cylinder. Any continuing cause leading to such cooling action such, for example, as the con tinued admission of Water carried with the vapor into the cylinder referred to in the previous example, or the action of radiation or the adiabatic expansion of the vapor, or any other cause, may in the end .result in so much heat being carried out through the eX- haust that any ofl these causes combined or alone would be so great when continued as to cover some portionof the wall surface with all the liquefaction it could retain. In other Words, any one such continuing cooling effect unless checked or prevented is cumulative and is sufficient to cause all liquebe raised to the proper temperature and then the amount of heat abstracted from the wall surfaces in contact with the vapor must not exceed the amount supplied at the said sur- 5 faces; otherwise, the Wall surfaces or any portion. thereof not responding to this requirement will present a lower temperature than that of the vapor and cooling on that surface will be cumulative until the surface is loaded with all the liquefaction it can carry.

In this invention this cumulative effect of cooling' in the cylinder is prevented, or controlled by superheating the admitted vapor, by eliminating moisture in any form from the admitted` vaper, by transferring heat from. outside sources through the body of the admitted vapor, and by jacketing the wall surfaces or supplying heat to said surfaces from outside sources, according to the particular conditions, and to an extent sufficient to prevent or control cooling at anyportion.- j

' Continuing the specific example hereinbefore stated for purposes of illustration, the cylinder may be surrounded with a steam jacket preferably at a tem erature by means of which the 'walls of t ecylinder v will be heated throughout to at least. the temperature of the incoming steam. orin this case, 358.260 F. lf now the admission valve be opened and one pound ofsteamcar rying 70 grains of moisture be admitted, the same result will occur as before, that is, the 355 moisture will be deposited on the walls and yno steam` will be condensed. When, however, the exhaust is opened and thevcontentsv passed into the condenser, heat will be abstracted from thev walls as befpre. Inthis 40 case, however, the 8.6 heat units taken froml the walls vare immediately replaced from the jacket steam, and .the walls assume the normal temperature for the next charge. 1f-

successve j operations are conducted rapidly .45 the walls may. .not quite recover their normal temperature,V more steam will be con-l v densed at each successive charge', tending still further to lower the wall temperature. However, through the inducing of a more Ikexample, byA raising the temperature of the jacket steam to asuitable degree, the operation of filling and exhausting the cylinderv successive' operationsa.v Referring again to the specic example given 1n illustration, 1t I rapid lowof heat through the Walls, as, for.

meaeae will be seen that the jacket must supply the 8.6 heat units or the latent heat of vaporization of the moisture. Practically the same result. would be secured in this example if 7070` grains of steam had been admitted to the cylinder, .the only difference being that 1192.2 heat units entered through the admission valve and 8.6 heat units through the cylinder walls. If it were desired to pass only 1191.2 heat units through the cylinder,

pressure less than 15.0 pounds absolute.

Because of the question of cost it may be undesirable so to jacket the surfaces as to prevent cooling at all points, that is, there may be restricted areas of the interior surfaces to which heat cannot be supplied in suiicient quantities from outside 4sources to prevent coolin without 'so increasingthe cost ofthe englne as to be undesirable, and again morder to secure a desired capacity it maybe desirable to permit cooling over certain restricted areas of these interior surfaces, but in either case the principles of the invention are retained because the amount of cooling is under control. In the foregoing the movement of the piston has been disregarded to simplify the consideration of cooling other than adiabatic. Likewise in now considering the matter of adiabatic cooling it will be considered separately. Neglecting therefore the effect of cooling due to other causes 'to thel moisture being evaporated at some p than adiabatic work performance, and assuming that dry saturated vapor is ad# mltted to the cylinder, the expanding vapor` moves the piston, the volume increases and the temperature of the vapor falls as the heat energy of the vapor is transformed into themovement of the piston. In such `a case where the energy is developed adiabatically by the expansion of the vapor,'the

energy originates all throughout the body of the vapor simultaneously and is then transmitted to the particular molecules or portion. of the vapor body in propinquity to the piston surface. The effect upon those molecules in immediate propinquity to the piston surface is similar to that in the' case of the molecules of vapor adjacent to the wall surfaces of the cylinder' already, described. The space relations of .the molecules adjacent to. the piston surface are decreased and their orbits contracted, resulting in cooling 'ofthe vapor in contact with the piston face. But the movement of the piston continues under the continuing.ex pansion of the vapor until the end of the stroke is reached and the cooling eEect has reached its maximum. During the travel of the piston, as the temperature falls due to adiabatic Work performance, cooling and partial re-heating of the vapor `Would continually take place, until the Work done would cumulatively produce more liquefaction than could be carried, but for the fact that the interchange of heat between the piston face and the vapor and later as the temperature of the vapor falls between the vapor and the other Wall surfaces prevent this cumulative cooling at the piston face being actually represented by liquefaction on the piston face.

The second principle involved in this invention is therefore that adiabatic cooling which is cumulative in its effects takes place on the face of the piston throughout the working stroke. The remedy is to supply sufficient heat to neutralize all cooling of the piston surface that may resultfrom adiabatic action. This is preferably performed by providing a chamber in the piston to constitute a jacket and feeding vapor thereto at the required temperature. Maximum efiiciency is secured by this invention when this cumulative cooling of the Wall surfaces is prevented at all points, the preferred Way being to admit onl v vapor of the highest quality available and to supply heat to the Wall'surfaces through the Walls from outside sources, to an extent suflicient to cause the pressure acting on the piston to follow the saturated curve, whenever after cut off the vapor has reached a saturated condition. This is because consumption of vapor diminishes with increase in quality of that admitted to the cylinder and because no heat furnished during the expansion from outside sources is Wasted, that portion passing to the Wall surface or the working vapor being all available for maintaining the'temperature of the wall surface orfor work performance and the balance vbeing" available for return to the generator as when the outside source is a vapor jacket. Any lessening of these conditions decreases the efliciency. It Will be apparent that the exhaust valve, the exhaust passages and parts adjacent areV peculiarly subject to cooling action because they are exposed to the cooling action of the entire body of vapor discharged from the cylinder at its lowest temperature. Hence it is important that any such surfaces so exposed should be constructed to present the minimum possible area and the construction by means of the jackets or otherwise should be such as to supply from out- 'also peculiar requirements.

vapor, of a material and With a surface of a shape and character to secure the conduction of the required or of a maximum amount of yheat to the surfaces and the transmission of the required or of a maximum amount of heat from the said surfaces to the Working vapor. The application of this principle to the various surfaces in contact with the Working vapor depends upon the particular conditions. The walls are by reason of the general conditions obtained divided into the three classes each subject to different conditions: (l) the piston Wall; (2) the exhaust valve, the exhaust passage and parts immediately in contact with the vapor discharged from the cylinder, and (3) the remainder of the Walls. The conditions acting at the piston Wall are peculiar because as has been pointed out adiabatic cooling takes place at the face of the piston. It is necessary in order to secure the maximum eficiency to transmit heat from outside sources through the piston Wall and from the face thereof to the Working vapor. The greater the area of the surface of the piston face, the greater amount of heat may be conducted therethrough, and. consequently this Wall must be so shaped and finished that it will absorb on one surface the greatest amount of heat and transmit to the other surface and from it to the Working vapor 4the greatest amount of heat in order to attain the maximum capacity. The shape of the piston face Will usually be controlled by practical considerations, but the finish or character may be readily varied as, for example, by scoring the surface With grooves having side faces inclined at an angle so as to multiply the surface area. rl`he larger this surface the more effective it should be. The material of the piston Wall is also of great importance in the matter of conductivity and, according to the conditions, that material should be used which will conduct therethrough the required or maximum amount of heat. In ordinary engines copper or brass in the order named may be used and the conductivity thus more than doubled over the ordinary iron piston. The surfaces of the exhaust valve, the exhaust passage and those parts in contact With the vapor discharged from the cylinder have Here it is necessary to have the material and the shape and character of the Walls such as to conduct the required or maximum amount of heat to the surfaces soas to maintain them at a high temperature. Furthermore, at

Kthis portion of the Walls it is essential that there shall be a minimum transmission of the heat from the surface to the vapor passing thereover in its passage from the cylinder. Hence, the shape and character of the wall surfaces at this area should be such as to cause the minimum transmission of heat from the surface to the vapor. This may be eected in various ways as by reducing this part of the surface as much as possible and giving it a smooth finish, and by providing it when possible with a coating which will minimize the transmission of the heat to the vapor. The surface of the exhaust valve exposed to the Working vapor should be reduced to the minimum area and preferably to an area not greater than that of the exhaust port. Means should also be provided for supplying heat to this surface as far as the conditions will allow by jacketing the valve itself vif possible or by other suitable means such as bringing the valve surface when the valve is open into contact with a surface to which heat is supplied from outside sources. The remainder of the walls, the `surfaces of which are in Contact with the working vapor should to secre the greatest capacity respond to the requirements of the piston wall, so far as constructional requirements will permit. The admission valves should alsobe constructed upon similar requirements to those just referred to in connection with the exhaust valve, as the admission valves are also exposed to extreme temperatures. It is also important that the construction of the engine at all points shall be such as to prevent so far as possible the retention or collection of moisture on any of the surfaces transmitting or absorbing heat, and at those points where the necessary configuration of the parts provides an opportunity for the collection or retention of moisture means should be provided for 'draining away any such moisture if it collects.' In general, therefore, capacity will be secured by having the material, shape and finish of all the walls such as to secure the transmission of a maximum amount of heat from outside sources to the interior surfaces and by having them such as to transmit from the wall surfaces to the working vapor a maximum amount of heat, ex-

cept at the exhaust surfaces where they are such as to secure the transmission of a minimum amount of heat.

The fourth principle involved is that capacity with economy is dependent upon the amount of heat supplied to the working vapor from the walls. It will be apparent that after cut ofI1 takes place'the heat units available in thecylinder for work performance are (1") those stored in the walls by the admitted vapor, (2) those arising from the reduction in total heat of the working vapor las it falls from initial to terminal pressure Lieeae Vthose transferred from outside sources independently of the working Vapor to the working vapor such as the cylinder and piston jackets, through the walls to the cylinder vapor. chieiy as a vehicle or carrier for the heat units supplied to it from the walls and transformed into work on the piston. rlhe heat which is abstracted from the walls by the workingvapor during the working stroke is all transformed into useful work and is thus of the highest eiiciency. It follows then that as much heat as possible should be transferred to the working vapor in this manner. This amount is materially increased by the increasing of the number of expansions which in turn means the increase in the range of temperature between 'lhe working vapor acts,

requirements will allow, subject to modiicay tions demanded by back pressure andclearance. This leads to the recognition of the next two principles. v

The fifth principle is that superheat adds to the economy and the capacity of the engine' with any given economy. The economy is increased because the same -weight of vapor entering the cylinder brings more heat units with it. These extra units are all transformed into work Without any loss taking place, thus the economy is increased because more work is done with the same weight of vapor. The capacity while maintaining any given economy is increased because with a given number of expansions the range of temperature will be increased, and thus the walls are more active in transmitting heat from the jackets to the vapor while the extra work done by heat abstracted from the vapor itself reduces the requirements from the jackets per stroke, hence the speed of the piston may be increased without causing the surfaces to become cooler.

The sixth principle of the invention is that while heat may be transferred from the admitted vapor before cut 0E and utilized in heating the walls, such methodof supplying heat is inefficient, and while heat may be transferred from the generator through the admitted vapor before eut off to the walls, and some or all this heat may be utilized in work performance, such method of supplyincense ing heat is likely to be inefficient, because any reduction in heat if not replaced before cut off reduces the quality of the vapor which as has Vbeen shown reduces the economy and the capacity with economy also. it will thus be seen that the economy and capacity of the engine are dependent upon the volume of vapor admitted to the cylinder, the thermal conditions, the structural characteristics affecting the thermal conditions, and the speed of the'piston,

all of which are interdependent. The chief structural characteristics affecting the thermal conditions have been pointed out and the principles upon which they should be designed or altered to secure the desired results have been pointed out and will be further described. The thermal conditions involve the quality, that is, the temperature, pressure and weight ofthe vapor admitted to the cylinder and the amount of heat supplied from outside sources independently of the working vapor to the working vapor which amount depends upon the character and extent of the sources as well as upon the other thermal conditions and upon the structural characteristics of the engine affecting the thermal conditions. lhe establishment of this principle of interdependence of all these elements now makes it evident that a change in any of them has its effect upon the efliciency and upon the capacity of the engine. This leads to the main or seventh principle of this invention.

The seventh principle of this invention is based upon the discovery and application of a fundamental and underlying` law which establishes the relation between the volume of vapor admitted to the cylinder, the structural characteristics affecting the thermal conditions, the thermal conditions and the speed of the piston by which no cooling` of the working vapor except that due to work performance is secured, and thus the highest efiiciency is attained. This means that whatis known as initial condensation is prevented and that the vapor follows what is known as the saturation curve when after cut ofi' it reaches saturation and is in the saturated condition at the end of the expansion. As has been pointed out, there is thus presented a ready and fairly accurate criterion for ascertaining the existence of the desired correlation of these elements. .lt also appears that some -variation in the quality of the vapor at the end of the expansion has coinparatively -little efl'ect upon the efficiency while producing a comparatively wide range in the capacity, especially if the vapor is of a higher quality. Hence, with the correlation established the capacity may be varied considerably without a substantial effect upon the efficiency. The application of this underlying fundamental law herein for the first time set forth and which has been termed the correlation of the volume of vapor admitted to the cylinder, the structural characteristics affecting the thermal conditions, the thermal conditions and the speed of the piston results in making the design and operation of the vapor engine a scientific matter whereas heretofore it has been the result of empiricism and experiment. Such experience and the empirical rules based thereon led to the generally accepted conclusion that economy increased with speed.` Hence it has never been possible, unless by some chance incapable of repetition under changed conditions, to bring actual and theoretical 'efficiency into coincidence. The principle of the present invention here under consideration is that there is a coperative relation between volumes of vapor admitted, piston speed, and structural characteristics affecting thermal conditions, and thermal conditions which must be established to secure the highest or any predetermined degree of efficiency. lith any of these elements given, the others must becorrelated therewith; and if any is varied, some or all of the othersv must be varied to establish or maintain this essential correlation. And it will be noted that this principle is adopted even when the efiiciency is lower than that attainable. The point iS that the application of this law of correlation enables the highest efficiency attainable to be predicted with accuracy and to correspond with the theoretical efficiency. It follows then that by varying one or more of the factors this efficiency may be decreased to any desired extent but the result thus obtained is reached intelligently and not by chance. So also within limits definitely established `by this law of correlation efficiency may be intelligently sacrificed vto any predetermined extent in order to increase the capacity.

By the application of this principle of correlation the designing of the engine becomes a matter of exact science. This principle further a'ords thel reason for sporadic instances of high efficiency which have been heretofore attained but which could not be maintained when one or more of the factors involved were varied. For example, it has been found that with an engine running at its most economical load very little saving is effected by using a acket` but when running with a light load the saving is considerable, while with an overload the jacket causes a loss of efficiency. In such a case this principle shows that the jacket was overworked in some part at least before vthe engine reached its most economical load under set conditions. `While, therefore, a series of tests might have indicated the best load for any aggregation of conditions it was imposf sible to determine how to improve those conditions. lf this principle of correlation had been applied to such a case to increase the MIC heat transmitted from the jackets to the required extent and thus to establish the proper relation between the thermal conditions and the other elements the steam consumption would have been much reduced at the corresponding load and the jacket or the-method of supplying heat to the interior surfaces from outside sources employed would have been found absolutely necessary for the attainment of this higher efficiency. It has also been demonstrated that when a high degree of superheat is used and some lheat is also supplied from outside sources that three or four expansions could be obtained without material loss due to cooling of the vapor on the surfaces but with a considerable loss attending a high initial pressure. Attempts to reducethis loss by materially increasing the number of expansions have resulted in further loss instead of gain in economy because the principle of correlation herein disclosed has not been understood.- So again, the importance of eliminating any moisture from the cylinder and the necessity of supplying heat to ldifferent parts of the interior surfaces to correspond with the differing requirements of those surfaces with the proper means for effecting these results have never been understood because of the lack of knowledge of the correlation of these thermal conditions and the other thermal conditions of the cylinder and the other elements which are necessary to produce the required efficiency.

Thus it has been found by experiment that an increase in the amount of moisture admitted to the cylinder means a proportionate increase in the amount of heat that is wasted, Whereas upon the application of the principles of this invention it is apparent that any moisture whatever admitted to the cylinder is not only a direct loss but if con-A tinued has cumulative eect which accounts forthe results heretofore secured because the correlation did not exist. It follows also that none of the means or methods hereinbefore set forth affecting any of the thermal conditions and none of the constructions devised for improving the engine in these particulars when used singly or together or in any combination can be of any value in attaining the maximum or required efficiency in the engine unless the various elements be correlated by chance.

The principles which have thus hereinbefore been set forth not only settle the main and vital features determinative of the method and apparatus but from them are readily deducible the principles which control other matters. Thus a reduction in clearance and areduction in back pressure will each permit of an increase in the number of expansions owing to the earlier cut off with the same load in one case and the lower terminal pressure allowable in the other, and each of these will not only increase the eiciency of the engine but also the capacity with any given economy. The timing of the moving parts, the conspicuous examples of which are the admission and the exhaust valves, affects the correlation, for example, a relatively early opening of the admission valve enables more heat to be transmitted from outside sources through the vapor to the interior surfacesl and a relatively early closing of the exhaust lvalve increases the superheating of the cushion steam.

In a welljacketed engine the cushion steam is highly superheated by compression on the return stroke of the piston and goes up rapidly in temperature under a nearly adiabatic compression. If no fresh steam were admitted it would expand along practically the same curve. The .use of the cushion steam for raising the temperature of the cylinder walls .does not present any direct economy in heat units because there has been a mere transference of the heat units from one side of the piston to the other. An indirect economy may, however, be effected by the increased number of expansions in the freshly admitted steam due to the more rapid fall in pressure of the highly superheated cushion steam. More than usual compression of the cushion steam may be advisable in special cases, as this compression may then be resorted to so. as

` to warm up the interior surfaces exposed to its action just prior to admission or so as to increasethe salvage with light loads.

Vater or moisture in an apparatus embodying this invention need not materially affect the economy but may only serve to reduce the capacity. It will be evaporated,

upon a reduction of piston speed, by the heat supplied through the jackets and will serve to advance the apparent point of cut off on the indicator card. In other Words this moisture instead of being evaporated in the boiler is evaporated in the cylinder. A failure to correlate the various elements would, however, be fatal to efficiency. For this reason suitable means for eliminating moisture from the admitted steam such as a separator would materially increase the capacity Without materially affecting the economy. j'

The main principles are thus broad and universal in their application, and details of design may be varied greatly within their scope. The small single cylinder steam engine under their application may be run with a degree of efficiency equal toor exceeding that of the multiple-cylinder engines of the present. Again it willbe observed that these principles in nearly every case increase both efficiency and capacity, that is adsense to say, the greatest horse power per unit of content of cylinder is obtained under the same conditions that make for the maximum of efliciency when saturated or slightly superheated steam is used. Existing types and constructions of engines may loe altered and regulated so as to radically improve their economy and capacity. 'lhe applica-- tion of these principles to that type of engine in which the speed is maintained substantially constant requires that the other elements shall be correlated to that speed, while in that type of engine in which the piston speed varies that the other elements must be correlated to the maximum piston speed or the piston limited to a speed which when 4correlated with the other eley ments secures the desired result. llhen this is eliected in the latter case as in the case of a locomotive engine the quality of the vapor at the end of the expansion when the speed reduces below the maximum is not reduced below saturation and the loss inefhciency is comparatively small even with some superheat in the exhausting vapor.

The ideal curve which should appear on an indicator card from an engine embodying and working under the principles herein disclosed with thesteam at the point of cut off in a saturated condition and with all interior surfaces dry may be readily plotted. It is the curve known as the saturated curve whose abscissas are the cylinder volumes at given points and whose ordinates are the pressures absolute of the corresponding yoliimes when the expanding steam continues in a saturated condition.- llf, `at the point of Vout oti, the vapor is superheated, the quality of the vapor will fall until the saturated condition is reached, While if the vapor is below saturated condition the quality will rise until the saturated condition is reached, and then, in either case, the ideal curve to the end of the expansion will be the saturated curve.

ln the designing of an engine to comply with this inventionor in the remodeling and regulating of an existing engine ditfcrent methods will naturally be followed dcpending upon the particular conditions. Until more data has been compiled and experience gained, the actual indicator card and the weighing test must be the final criterion for deciding` the economical limit ot speed of the engine. This speed is not too 4great if the terminal pressure be found to be that due to saturated steam of a volume equal to that-of the cylinder and of a Weight equal to the weight of steam admitted to the cylinder after making allowances` such as for the clearance. If the terminal pressure is low from too high a speed it will be vrapidly followed by the cumulative losses rcferred to and a consequent loss in economy.

and .the 'toe of succeeding indicator cards will show a high pressure instead of a low. lf the terminal pressure is high from. too

low speed it indicates superheat passing into the exhaust. y rllhis would rarely occur with any economical expansion because Vit would indicate that the vapor was absorhcapacity.

Correlation, as disclosed herein, of the amount of heat contained in and supplied to the Working vapor and the surfaces in contact therewith with the other elements as disclosed means control of the temperature of these surfaces; but such control is deter'-l minative of thecondition or quality of the working vapor in the cylinder. By the quality of the vapor is here meant the quality of the contents of the cylinder including such moisture yas may be present either in the vapor or on the surfaces. lhere is thus presented a tangible practical criterion for this invention, because the weight, volume and pressure and consequently the qual- -ity of the working vapor is readily and accurately ascertainable. The highest effi- -ciency in reciprocalole engines will be secured by this invention when the working vapor follows the saturated curve to the' end of the expansion whenever after cut od the vapor has reached a saturated condition. t is also considered that the information herein given is sucient to enable anyone skilled inthe art to test an engine and de= cidewhen the principles of this invention have been complied with. Slight departure from the theoretical perfection are of course Within the scope of the invention. For example, .withyery hot steam in the jackets it is clear that some surfaces'may be cooled at thc end of the stroke, and still recover enough in temperature during exhaust to prevent the temperature of the surfaces loeing lowered for the next admission. lln such a case the indicator card would probably show a more hollow curve than the theoretical saturated vapor pressure curve herein described and the economy would not be so good, but the cumulative cooling would nevertheless be under control. ln any two engines variations in exact result are likely to occur although the cnonditions are apparently similar. 'The material and. homogeneity of the walls, the areaand finish of the surfaces, and the freedom with which steam ills the cylinder will al1 adect theresults.

A speciic illustration may be interesting and may serve to add to an understanding of the application of the principles of the invention. The figures used are taken from Peabodys well known tables and the condipounds absolute pressure is used, having enough superheat in it so that it arrives at the point of cut off saturated and with the surface of the piston and interior surfaces o f the cylinder dry; and that the back pressure is 1 pound absolute. Up to cut off there is admitted 1 cubic foot or .3685 pounds of steam or l During this period Work has been done in propelling the piston amounting tto The Work done during the piston stroke will be that due to a mean effective pressure of close to 32% of the initial pressure. This precentage may be calculated or taken from :30.5 B. T. U.

the saturated'vapor curve already described.

This amounts to 1 65 X .32X 144X 10.

778 =96.4 B. T. U.

The back pressure amounts to 1 X 144 X 10 T- B. T- Us The terminal pressure will be that due to' saturated steam which Weighs per cubic foot or practically 14.122 pounds per square inch. There is then exhausted 1146X.3635=416.57 B. T. U.

There are therefore 4:33.87-416.57=17.30 B. T. U.

less in the steam which Were converted into Work through the drop in total heat Without any need of evaporation taking place on the piston for vthis amount of Work.

v The total effective Work is 96.4-.1.85=94.55 B. T. U.

The total heat units admitted to the cylirler for doing work up to the point of cut o 1s 433.87+30.5=464.37 B. T. U.

The heat units abstracted from the piston aacsaa in evaporating adiabatic condensationl are then 4 eea- (30.5+17.3) :48.6 B. T. n.

The heat units returned in the feed Water to the boiler at the condenser temperature of 101.99 O F. are

70X.3685:25.44 B. T. U.

The total heat units chargeable to the cylinder are, therefore,

464.37-|-48.6-25.44=487.53 B. T. U.

0f these the heat units doing eiiicent Work are v964-1852:94.55 B. T. U. The eliiciency is then directly and Without revaporation or reheating taking place; (ai) by constructing the Walls of material of high heat conductivity with surfaces (e) shaped and (f) finished to transmit the maximum amount of heat.; or in the case of the walls adjacent the exhaust, to transmit the minimum amount of heat; (g) by using the highest temperature of Steam possible in the jackets (h) by returning the feed Water to the boiler at as high a temperature as possible; (i) by reducing 'the clearance to the minimum which mechanical conditions Willpermit; and (j) by preventing so far as possible moisture from being carried in to the cylinder With the admitted steam; (k) by reducing as much as possible the heat transmitted to the exhausting vapor. 'A moderate amount of cushioning is also an indirect help for the reasons already pointed out.

. The capacity of-this engine may be determined inthe following manner. Assuming the use of a turned yiron piston which may transmit about 300 B. T. U. per square foot per hour per degree difference in4 temperature, the temperature range will vary from 365.88o F. to 210 or the difference of 155.88". A question arises as to just What portion of this difference in temperature would be available. The fall is very rapid at the start and very slo-W at the end; again the piston surface has a chance to recuperate during exhaust if not overcooled, so it will` be assumed that the total difference is available or 155.823)(3002467@ B. T. U.

that are transmitted through the surface in one hour. But it was found that i813 units are absorbed from the piston in each stroke G fg2= 100.4 feet per minute.

total capacity from both sides of a smooth iron piston Melsq. in. in area, but it will be found on investigation that each change that helps economy will also help capacity.

`While the true capacity has not yet beenl accurately determined experiments show that this figure is Very conservative. A grooved iron piston ora copper piston instead of an iron piston, for example, would alone about. double this capacity. `When conditions are altered from present standard to-conform with these requirements then the limit of speed will be setby the construction of the engine itself and the greatest capacitywill be obtained under the same conditions that give the greatest economy, unless in an eXtreme casefwhere superheated steam is used with a late cut off.

The data for these calculations are at present somewhat limited and an error may be made in judgment without affecting the essential principles involved. The calculations are simply illustrative. The final test must be the efficiency of the engine which should conform fairly closely to that found for thel assumed conditions. Verification may be had by an actual determination of steam consumed or by the use of the indicator alone. lf the expansion curve be found to correspond as described with the saturated curve described conditions cannot be far from right. And if not, corrections can then be made accordingly. p

ln this example work was performed before cut ofil by heat abstracted from the vapor contained between the piston and the superheater, the final result assumed being the reduction in temperature or quality of the vapor in the cylinder at 'out 0H until it reached the point of saturation. As a result'l the density was increased, and the eX- haust loss was proportionately greater.

This will be a small capacity equivalent Had the cylinder at cut off contained vapor 50 superheat, then the loss at the en .haust port would have been about 8% less, while the work done would he almost iden-n tical. Also because heat abstracted from this vapor during expansion would replace some of the units abstracted from the walls in the example given, the. piston velocity, or capacity, could be proportionately increased, while the greater difference in temperature between initial and terminal pressure would again make the walls more active in transmitting heat from the jacket, thus allowing a still greater increase in Velocity.`

No allowance was made for any heat abstracted from other than the piston surface, so the figures obtained should give a liberal margin allowing for some variations in expansion and the edects of clearance. lf the surfaces become cooler, they will be heated by the incoming steam in the manner described but this is not the preferable manner because there is almost certain to be some fall in the quality of the steam as a result with the attendant fall in efficiency also, and if this method is carried to extremes the liquefa-ction described takes place and the benefit of the jacket is lost.

lf this method is resorted to at all, it is wellto advance the lead of the inlet valve, thereby allowing molecular interchanges to replace some of the heat lost while the piston moves slowly over the dead center; for the same reason a large inlet port and free passage are desirable in order to maintain the quality of the vapor up to the point of cut off, as if it is subject to the cooling action of low temperature surfaces up to the point of cut off as well as that due to work performance on `the piston,.then the more of this heat that'is supplied by vapor outside the cylinder and in Contact with the heatsupply, the less the .reduction of heat in the vapor in the cylinder andthe higher its temperature when cut-off occurs and for a given result a largel free passage way for the steam permits of a higher piston velocity in all cases. Similarly small clearance gives more expansions for any `definite amount of y work performance and it adds therefore to the eflicient capacity as well as to the efliciency. ln the example lgiven clearance has beenneglected but the effects of clearance and back pressure can be calculated by Welll known formulae.

The single figure 7of drawingl presented herewith illustrates `mainly diagrammatically an engine cylinder and connected parts. This drawing is presented not for the purpose of disclosing any structural details, but simply to aid in a disclosure of the invention, which it will be observed is not limited to any specific form of engine or to any specific form of construction for securing the desired results. But for reasons which are apparent the engine should be capable of carrying high pressures, of running at any speed desired and the valves should be adapted for running with superheated steam and the clearance should be small to secure the best results.

Many of the structural features separately considered which are necessary to the construction of an engine embodying this invention or to the carrying out of the process of this invention are probably old, but never before have they been combined and correlated on theprinciples of this invention and to secure the results secured by this invention.

In the drawings the engine cylinder is indicated at 1, the piston at 2, piston rod at 3, the connecting rod at 4 and the iy wheel at 5.

`The steam chest 6 is connected by the admission ports 7 and 8 with the interior of the cylinder. These ports are arranged to enter through the heads of the cylinders. The admission ports are controlled by valves 9 and 10,-respectively, which may be of any suitable construction and are herein shown as of the plug type.A The seats for these valves are elevated slightly above the bottom of the steam chest so that no moisture can drain from the steam chest into the valves and through the ports, and the steam chest itself is provided with a suitable drain such as shown at 11 to drain off any moisture which may collect therein.

Theexhaust ports 13 and 14 are located at a suiiicient distance from the end of the cylinder to allow the piston at the end of its stroke to pass over and cover these ports thus enabling a minimum clearance to be obtained and also preventing the fresh steam passing through the admission ports from coming in contact with the exhaust passages and valves until the piston has uncovered them, thus giving them considerable time to be warmed up before coming in Contact with the freshly admitted steam. These exhaust ports are controlled by suitable valves 15 and 16 herein shown as of a similar type to the admission valves. It is important that all these valves shall fit snugly so as to prevent any leakage, and any suitable means may be employed for maintaining the fit and compensating for wear such as the standard expansion features which it is not necessaryhcrein to illustrate. These four valves are all controlled by suitable valve mechanism herein indicated as operated by the rod 17 extending to the eccentric 18 and controlled bythe governor 19, all in a familiar manner, to admit the steam to and exhaust it from the cylinder at each side of the piston. The governing and controlling mechanism allows any predetermined 0r variable degree of cut 0H. The entire cyl- Licenze 1t has been found out that the surfaces ofthe exhaust passage and those parts in con tact with the vapor discharged from the cylinder require particular attention. For the reasons set forth, the jacketed space 23 is arranged to surround so far as possible the exhaust passageway andY Valve and the exterior of the cylinder at this area is ribbed and grooved as shown at 25 to assist in securing transmission of heat from the jacket to the passageway and valve. The bottom of the cylinder itself is also subjected to more cooling action than the top because if any moisture is admitted to or occurs in the cylinder it will pass by gravity to the bottom and to aid in securing the transmission of the necessary amount of heat to this portion of the cylinder it may also be provided with ribs and grooves 25. The walls of the exhaust passageways between the surfaces of the cylinder and the valve may also be finished as smooth as possible and provided with a coating such as that recommended by Prof. Thurston to prevent so far as possible the transmission of the heat to the exhausting vapor. The construction thus illustrated serves also to heat, when the exhaust valve is open, the surface of the valve which when closed is exposed to the higher temperature of the admitted steam.

Spaces are indicated in the body of the four valves which may be filled with air or connected to the jackets.

The piston 2 is formed to present the hollow interior 26. Its face Walls should Ybe made of suitable material as explained in order to secure the desired transmission of heat, and copper and brass are suggested for that purpose, although other suitable materials may be used. The outer surfaces of the piston are shown as provided with concentric ribs and grooves 27 and the inner surfaces with vertical ribs and grooves 28 thus increasing the area of those surfaces and their capability of heat transmission. The interior surfaces of the cylinder heads may also be as shown, provided with similar concentric ribs and grooves, thus increasing all the jacketed clearance surfaces excepting those of the exhaust port which should be as small as possible.

It is advisable not only to supply steam to the interior of the piston but to have a little circulation through the piston, thus preventing the formation of or clearing out of air I is eclmeel ee the iep of `elle bellow neer ef the piston and passes out the lee'tem @MT5/ing with it any slr. shown es passing from the hollow nterley of he piston so elle cylinder jacket er alle space 23.

The piston refl 3 s madehellew es shown 'et 29 and passes ftlne gli a suitable sueg loes.' 8.0 through lle jacket and cylinder enel ml@ elle ejflmeler, and bel/lee mie the plsten. A plpe 3l; commumeates meh lle mierlo 29 ef the pieten reel and; exends up new@ te 'elle iep elf tee i e drainage poel; 32 is prcevdenl e drain any meseu'e imm elle piston rod, he pipe 33 leacls fte *elle seam supply 01' laeiler e sul'elele eeimeetee is merle te "eee hollow me'er 0f the piston, enel pisen reel which in ehe :form shown eem- @e Lmlzeel es a supply ee lflef 'zlssa @impose elonga'eel easing, cured. te easng; 'heeel 2l. eve-ey i w 'elle pie A pipe eeeeeees ex'encls ehe nere elf easing; 38 fe 'le e suitable semee en. "apply e pipe e@ ee the top Valves el, lf2 enfle-3 efe wrevlelecl 'espec'tively 1n e l0 leedie :lieg l' belle? te -L E e, steC 0:5 dill/erenteme supplied. le Ie. fe ej ee jelet of the be supplied imm elesleflt, el" @leien jee heel leem 'e -e ejfllmfile jnel-e ,if uwee.

Tl engine ils sel; j ecmbljy efe a higllef evl than thee 0I" elle "Wae' level in belle? se my ceniensel'ien 'from he jecles may drain beek, te .elleie Ssi'elale ai? valves f-S are e e mejfle epene. eccesenelly er elsermosbefhle Kwvalves may be supple,

lila has been 'explalnel *allee if@ is el eresia impetance -llje's mesrfame muse ee elimimmbefl rem elle steam @flier The Sleen@ is der e ferm ef separator as one means for securing this esult isl illustrated ai: 19. Seem passes llu'eughthe supply pipe' 50 into elle sepamfwq and from thence hcfough the tipe 51 in@ falle seam chesE elle moisture heyerom being elimlnateflenel dmned away by the separa-bola The jacket spaces 24: l 2

A e surround 'elle seem jacket, keepmg steam 1n best joosslble cemlltlon unl is delivered thzegh the admission pews 'mee elle cj/lmder.

Ne ''aemp has been macle 'lso lustete or deseiee rleels of construction because these will loe readily unclerseecl ple vflecl iger by any' one familie? 'Wsh engine @enel/sfu lenu llfb will' be mdesteed "elise 4she @tempereiure the surfaces in cominci@ We ehe Wo, eg; nvape? is a lmceenfof the amount 01": e. el; suppleel *be bhese surae s and the amount of heeg ebstracfecl llerefmm The eempemm'e ef 'lle lxeeing egen er "the heal: supplied. :from euscle sources will delzemine zempememe 'im which the surfaces can lee aiseel, While-'lle temperature of these sm'eces dwing ahe epeaxbeie ef the engine will be eleeminecl by 'elle amount ef heet tibet 'the Wells can transmit e@ ehem and by 'lle emeune ef heat "elslsmce from thenh The ineens fm: supplvngllea;

Outside se's'ces nclependenely of lle Werking v ei ceurse includes 'the same source es t@ J ef `the 'Weflilng vapolr, eueV the Werling veeel* 'is preferably not dlawn' leugll the l Pee.

heel; sdpplecl 'em @Reside som-ces elen'tly of the Werking vapolf is that heel, "l clw` is supplied. through elle wells or te 'mp aclmatee te lle cylimcle, by eenducien cenvecem eh 4lj elle per flselfj but Wheu; reducmg elle said mp0? #L any tim'l mssen te elle cyl'nde. Su elfes seme o? ell ef the new. e .m'zvl Le the eine cflleze jf eesirecl.

l l the Vapor Yu elle meef will necessmilj7 very as u' is nceeeeel diminished. The principles lem be eeeueel in 'elle e veelelens when the average quality ef 'elle mp0? lle end of elle efpansen er the evemge quality ef prior application Se. No.` 684,396, filedv March 18, 1912, for method 'and apparatus for obtaining work from Vapor.

Having fully described my invention, what l claim as new and desire to secure by Letters Patent is:

`1 l. rlhe method of obtaining Work from a vapor engine comprising cylinder with a piston vreeiprocahle therein, which consists in admitting vapor to the cylinder, in supplying heat from outside sources independin admitting vapor to the cylinder, in sup-v plying heat from outside sources independently of the Working vapor to the/Working Vapor, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics a'ecting thermal conditions, the thermal conditions, and the piston speed to prevent initial liqueiaction. p n

3. The method of obtaining Work from a vapor engine comprising a cylinder with `a piston reciprocable therein which consists in adntting vapor to the cylinder, in supplying heat from outside sources independently of the working Vapor to the Working vapor, andnin correlating the Volume of vavpor admitted to the cylinder', the structural characteristics affecting thermal conditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion.

fl. |The method oi'obtainin'g Work from a vapor engine comprising a cylinder with a piston reciprocable therein which consists in admitting Vapor to the cylinder, in supplying heat from outside sources independently of the Working Vapor to the Working Vapor, and in correlating the volume ci' vapor admitted to the cylinder, the structural characteristics atiecting thermal conditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall :follow the saturated curve to the end of the expansion Whenever after out off it reachesa saturated condition. l

5. The method of obtaining Work from a Vapor engine comprising a cylinder withl a piston reciprocalole Vtherein which consists in admitting-Vapor to the cylinder, in supplying a predetermined amount of heat from outside sources independently of the working vapor to the Working Vapor, and in correlatin .3 the volume of Vapor admitted to the eylin er, the structural characteristics incassa affecting thermal conditions, the thermal conditions, and the piston speed t0 secure a predetermined capacity and insure the vapor being in a saturated conditionat the end of the expansion.J

6'. 'llhe method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein which consists in yadmitting vapor to the cylinder, in supplying a predetermined amount of heat from outside sources independently of the Workingyapor to the Working vapor from predetermined surfaces in contact with the Working vapor, and in correlating the volume of Vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the thermal conditions, and the piston speed to secure a predetermined capacity and insure the Vapor being in a saturated condition at the end of the eX- pansion. v

7. rlhe method of .obtaining Work from a esA Vapor engine comprising a cylinder with a piston reciprocable therein which consists in admitting vapor to the cylinder, in supplying heat :trom outside sources independently ot the Working vapor to the Working vapor, and lin correlating the volume of vapor admitted to the cylinder, the structural characteristics adecting thermal conditions, the quality of vapor admitted to the cylinder, the other thermal conditions, and the piston speed to insure that the Vapor in the cylinder shall be in a substantially saturated c'ondition at the end of the expansion.

8. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reeiprocable therein which consistsin..

admitting vapor to the cylinder, in supplying :a predetermined amount or" heat from outside sources independently of the workingyapor to the Working vapor, and in correlating the Volume of vapor admitted to the c` linder, the structural characteristics aiiectlng thermal conditions, the heat so supplied, the other thermal conditions, and the piston speed to regulate the amount of heat abstracted from the Working vapor.

9. rilhe method of obtaining Work from a Vapor engine comprising a cylinder with a piston' reciprocable therein which conlll@ sists in admitting vapor to the cylinder, in

supplying a predetermined amount of heat from outside sources independently of the Working Vapor to the Working Vapor from predetermined surfaces in Contact With the Working vapor, and "in correlating the Volume ovapor admitted to the cylinder, the structural characteristics aiiecting thermal conditions, the heat so supplied, the other thermal conditions, and the piston speed to regulate the amount of heat abstracted from the Working Vapor. l

l0. rll`he method of olotaining'work from a Vapor englne comprising a cylinder with a rially cooling the vapor prior i piston reciprocable therein which consists in admitting vapor to the cylinder, in supplying heat from outside sources independ-- ently of the Working vapor tothe Working vapor, in exhaustingthe main body ot the vapor at alternate strokes from opposite ends of the cylinder, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics adecting thermal conditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion.,

ll. The method of obtaining Worlr from a Vapor engine comprising a cylinder with a piston reciprocable therein which consists in admitting vapor to the cylinder, in supplying heat f-rcm outside sources independently of the Working Vapor to the Working Vapor, in exhausting vapor at alternate strokes through separate ports at opposite sides of the center of the cylinder, in supplyiinA heat from outside sources independently or the Working Vapor tothe surfaces adjacent said ports which are ezqposed to the higher temperature of the Working Vapor, and correlating the Volume of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the heat so supplied, the other thermal conditions, and the piston speed to insure thatthe Vapor in the cylinder shall he ina substantially saturated condition at the end ol the ein parisien. A

12. rl`lie method oi obtaining Worlr Vlroin a vapor engine comprising a cylinder 'with a piston reciprocalole therein which consists in admitting vapor to the cylinder, in preventing the vapor in the cylinder from materially cooling the vapor prior to its admission the cylinder, in exhausting Vapor alternate strokes through separate ports at opposits sides oil the center ot the cylinder, in supplying heat from outside sources independently of the Working vapor 'to the surlaces adjacent said ports which are exposed to the higher temperature oiE the 1Worlting Vapor, in supplying heat from outsidel sources independently of the Working Vapor to other surfaces, and in correlating the volume of vapor admitted to the cylinder,

the structural characteristics affecting thernaal conditions, the heat so supplied, the other thermal conditions, and the piston speed to insure that the vapor in the cylinder shallloe in a substantially sa urated con-- dition at the end oi the expansion..

l. ylhe method of obtaining Werl: from Vapor engine comprising a cylinder 'with a piston reciprocahle therein which consists iii admitting vapor to the cylinder, in prevent-- ing the yvapor in the cylinder trom ts adniisinto the cylinder, in heat `he other thermal conditions will insure that (lil from outside sources independently of the Working vanor to the face of the piston and to other surfaces in contact with the working vapor, in exhausting vapor at alternate strokes through separate ports at opposite sides of the center ol2 the cylinder, and in correlating the Volume of Vapor admitted the cylinder, the structural characteristics affecting thermal conditions, the heat so supplied, the lother thermal conditions, the piston speed to insure that the Vapor in the cylinder shall be in a substantially saturated condition at the end oli the expansionc lil. The method of obtaining Worlr from. a vapor engine comprising a cylinder with piston reciproc'ahle therein which consists in admitting Vapor to the cylinder, in supplying heat from outside sources in dependently of the Working vapor to the Working vapor, and in limiting the piston to a speed which correlated with the roll nine of vapor admitted to the cylinder, the structural characteristics aliecting therme conditions, and the thermal conditions Wil .i that the vapor in the cylinder shal he in a substantially saturated condition a end. ot the expansion.

l .ie niethod oit obtaining Werl?. i

Vapor engine comprising a cylinder im, iston reciprocahle therein, which congli ' rists in admitting Vapor to the cylinder,

supplying heat from outside sources pendently of the Working vapor to the 'Werli- Vapor, and in limiting the piston to a speed which correlated with the Volume oi' `vapor admitted to the cylinder, the timing of the moving parts, the structural characteristics affecting thermal conditions,

ie vapor in the cylinder shall be in a su tantiaily saturated condition at the end of the asien.

llt i method of obtaining Work i" yor engine comprising a cylinder with ton reciprocahle therein, which consists admitting vapor to the cylinder, in sup-- troni outside sources independtiie Working vapor through the cylr and piston 1walls to the Working Vapor, limiting the piston to a speed which correlated `with the volume of Vapor admitted to the cylinderq the structural characteristics atlecting thermal conditions, the heat so supplied, and the other thermal conditions, will insure that the taper in the cylinder shall he in a substantially saturatel condition at the end of the expansion.

lThe method of obtaining work from Olli l a vapor engine comprising a cvlinder with 4. w Y I. a 'it the eaha 'ort, in suonlying n from outside sources independently otfthe Working vapor to other` surfaces in contact with the Working Vapor, and in limiting the piston to a speed Which correlated with the volume of Vapor admitted to the cylinder, the structural characteristics adecting then mal conditions, the heat so supplied, and the other thermal conditions, Will insure that the vapor in the cylinder shall be ina substantially saturated condition at the end ot the expansion. .4 v

18. Themethod of obtaining Work from a vapor engine comprising a cylinder with va piston reciprocable therein, which contiti -gree dierence in temperature todos trans-V sists in admitting Vapor to the cylinder, in supplying; heat from outside sources independently ot the Working); vapor to the Work-I ing Vapor, and in correlating'the volume of Vanor admitted to the cylinder, the structural characteristicsY affecting thermal conditions, the thermal conditions,and the piston speed to establish and maintain, during any, variation in the number of expansions demanded by the Variation in the load up to the point When the terminal. pressure is reduced belowr the exhaust pressure, such ternperature of the surfacesin Contact With'the Working Vapor as are necessary to insure that the -Vapor in the cylinder at the end of the expansionl shall be in not less than a substantially saturated'condition.

19; The method of obtaining Work from' a vapor engine comprising a cylinder `Witha piston reciprocabletherein, which consists in 'admitting vapor to lthe cylinder, in sup plying heat from outside sources independently ot the Workingv vapor to the Working vapor, and in correlating'the Volume ot vapor admitted to, the cylinder, thel structural characteristics adecting thermal conditions, the thermal conditions and the piston speed to establish and maintain., during1 any variv ation. in the number ot expansions demanded by"-the Variation in the load, suchtem peratures ot the surfaces in contact with,

theworking vapor as are necessary to insure that the Vapor in the cylinder at. the end of the expansion shall be in not less than al substantially saturated condition.

20., rJhe method ot obtaining Work from a vapor engine :orn'prisingI a cylinder With a piston reciproca'ble therein which consists v,in vadmitting to the cylinder Vapor with sut icient superheatto permit of some expansion and of a volume which upon expansion requires the greatest amount of heat per de- Lisanne insure `that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion, whereby the number ont expansions may then be increased or decreased indefinitely Without causing lthe yapor to be belen7 a substantially saturated condition at the, end of the expansion.

2l. rlhe method of obtaining Work from a vapor engine comprising a cylinder with a piston reciprocable therein, which consists in admitting to the cylinder vapor with sufiicient superheat to permit oir' some expansion and of a volume which uponexpansion requires the greatest amount of heat per degree diiierence in temperature to be transmitted from outside sources to the Working vapor, in supplying heat 'from outside sources independently of the Working Vapor to the Working Vapor, in exhausting the main body of the Vapor' at alternate strokes from opposite ends of the cylinder, and in correlating the Volume and quality of Vapor admitted to the cylinder, vthe structural characteristics aeoting thermal conditions, the other thermal conditions and the piston speed to insure that the Vapor in the cylinder shall be 1n a substantially saturated condition at the end of the expansion,v

whereby the number of expansionsmay then be increased or decreased indefinitelywithout causing the vapor to be below a substantially saturated condition at the end or the expansion.

22. The method of obtaining Work from a 'vapor engine comprising a cylinder `with a'piston reciprocable therein, which consists in admitting vaporto the cylinder, in sup- 4 plying heat from outside sources independently of the Working vapor to the Working vapor, and in correlating the Volurneiof Vapor admitted to the cylinder, the structural characteristics aecting' thermal conditions, the thermal conditions, and the piston speed to cause more heat to be transmitted to the .Working vapor during the Working stroke than 'is abstracted from or through it by the surrounding Walls and to insure that the Vapor shall be in a substantially saturated condition at the end of the expansion.

v 23. rlhe method vof obtaining," Work from a vapor engine comprising a cylinder with a piston reciprocable therem, which consistsin admitting to the cylinder'vapor in a saturated or slightly superheated condition and of such a quality as to be in a saturated condition at or before cut od', in supplying heat `from outside sources independently of the Working Vapor to some of the surfaces in 'contactjvvith the Working vapor, and in correlating the volume and quality'ot Vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the other thermal condltions, and the piston `speed to insure that the vapor shall be in a iaeaeae substantially saturated condition at the end of the expansion whereby the correlation Will be maintained regardless of any increase in the number of expansions.

24. The method of obtaining Work from a vapor engine comprising a. cylinder `With a y,piston reciprocable therein which consists :in` admitting to the cylinder vapor in a satu-l rated or slightly superheated condition and of such a quality as to be in a saturated condition at or before cut off, in supplying heat from outside sources independently of the Working vapor to some of the surfaces- ,in

contact With the Working vapor, in exhausting the main body of the vapor at alternate Vstrokes from opposite ends of the cylinder,

and in correlating the volume and quality of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the other thermal conditions, and the piston speed to insure that the vapor shall be in-.Jasubstantially saturated condi- ,tion at the end of the expansion whereby the correlation will be maintained regardless of any increase in the number of expansions.

25. The method of obtaining work from a vapor engine comprising a cylinder With a piston reciprocable therein Which consists in admitting vapor tothe cylinder, in supplying heat from outside sources independently of the working vapor to the surfaces adjacent the exhaustwhich are exposed to the high temperature of the freshly admitted vapor, in supplying heat from outside sources independently of the Working Vapor to other surfaces in contact with the Working vapor, and in correlating the volume of Vapor admitted to the cylinder, the structural characteristics aecting thermal conditions, the heat so supplied, the other thermal conditions, and the piston speed to establish and maintain during the operation of lthe engine such temperatures ofthe surfaces in contact With the Working vapor as are necessary to cause the vaporin the cylinder at the end of the expansion to be in not less than a substantially saturated condition.

26. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein Which consists in admitting vapor to the cylinder, in supplying heat from outside sources independently of the Workingvapor to the surfaces of the exhaust valve Whichare exposed to the high temperature of the freshly admitted vapor, in supplying heat from outside sources independently of the Working vapor to other surfaces in contact with the Working vapor, and

in correlating the volume of vapor admitted Working vapor as are necessary to cause the Vapor in the cylinder at the end of the expansion to be in not less than a substantially saturated condition.

27. The method of obtaining Work from a vapor engine comprising a cylinder with a piston reciprocable therein which consists in admitting vapor to the cylinder, in supplying heat from outside sources independently of the Working vapor to the surfaces of the exhaust valve and the surfaces adjacent the exhaust Which are exposed to the high temperature of the freshly admitted vapor, in supplying heat from outside sources independently of the Working vapor to other surfaces in Contact With the Working Vapor, and in correlating the Volume of vapor 'admitted to the cylinder, the structural characteristics affecting thermal conditions, the heat so supplied, the other thermal 'conditions, and the piston speed to establish and maintain during the operation of the engine such temperatures of the surfaces in contact with the Working Vapor as are necessary to cause the Vapor in the cylinder at the end of the expansion to be in not less stantially saturated condition.

28. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein, which consists in admitting Vapor to the cylinder, in supplying heat from outside sources independently of the Working vapor to the surfaces adjacent the exhaust which are exposed to the high temperature of the freshly admitted vapor, in supplying heat from outside sources through the piston Wall to the face thereof, in supplying heat from outside sources independently of the Working vapor to other surfaces in contact with the working vapor, and in correlating the volume of vapor admitted to the cylinder the struetural characteristics affecting thermal conditions, the heat so supplied, the other thermal contact With the working vapor as are necessaryto cause the vapor in the cylinder at the y end vof the expansion to bein not less than a substantially saturated condition.

29. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein, which consists in admitting vapor to the cylinder, in supplying heat from outside sources through the piston Wall to the face thereof, in supplying heat from outside'sources independently of the Working vapor to other surfaces in contact with the Working vapor, and in correlating the volume of vapor ad-I mitted to the cylinder, the structural characteristicsaiecting thermal conditions, the heat so supplied, the other thermal conditions, and the piston speed to establish and maintain during the operation of the engine such temperatures of the surfaces in contact with the Working vapor as are necessary to cause the vapor 1n the cylinder at the end of the expansion to be in not less than a substantially saturated condition.

30. The method of obtaining work from a vapor engine comprising a cyli-nder with a piston reciprocable therein, which consists in admitting vapor to the cylinder, in supplying heat from outside sources 1ndependently of the working vapor to the surstructural` characteristics affecting thermal conditions, the heat so-supplied, the other thermal conditions, and; the piston speed to establish and maintain during the operation of the engine such temperatures of the surfaces in contact' With the Working vapor as are necessary to cause the vapor in the cylinder at the end of the expansion to be in not less than a substantially saturated condition.

31. The method of obtaining work from a vapor engine comprising a cylinder with a piston reciprocable therein, which consists in admitting vapor to the cylinder, in sup-' plying heat from outside sources through the cylinder end Walls to the faces thereof, in supplying heat from outside sources independently of the working vapor to other surfaces in contact with the working vapor, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the heat so supplied, the other thermal condif tions, and the piston speed to establish and maintain during the operation of the en-4 gine such temperatures of the surfaces in contact With the Working vapor as are necessary to cause the vapor in the cylinder at the end of the expansion to be in not less than a substantially saturated condition.

The method of obtaining work from a vapor engine comprising a cylinder with a piston reciprocable therein, to. secure a predetermined capacity which consists in admitting vapor to the cylinder, in eliminating moisture to the extent required to secure the said capacity from the vapor `admitted to the cylinder, in supplying heat from outside sources independently of the working vapor to the working vapor, and in correlating the volume and quality of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the other thermal conditions, and the piston speed to cause the vapor in the pendently of the working vaporv to the l working vapor, in exhausting ti'he Vapor from the cylinder Without bringing it into material contact with the Walls exposed tol the Working vaporv in the cylinder and thereby preventing cooling of the working vapor by the exhaustedvapor, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics laffecting thermal conditions, the thermal conditions, and the piston speed to'insure that the vapor in the cylinder shall be in a substantially saturated Vcondition at the end of the expansion.

84. The method of obtaining Work from a vapor engine comprising a cylinder with a piston reciprocable therein, vWhich'consists in admitting vapor to the cylinder, in preventing material cooling of the Vapor prior to its admission into the cylinder by the vapor in the cylinder, in exhausting the vapor from the cylinder Without bringing it into material contact with the Walls exposed to the Working Vapor in the cylinder and thereby preventing cooling of the Working vapor by the exhausted vapor, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the thermal conditions,`

and the piston speed to insure that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion.

35. .The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein, Which consists in admitting vapor to the cylinder, in supplying heat from an outside agent through the Walls to some of the interior surfaces, in automatically maintaining the exterior surfaces in condition to abstract heat freely from the said agent, and in correlating the volume of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion.

36. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein, Which consists in admitting vapor to the cylinder, in supplying heat from outside sources independently of the Working vapor to the Working Vapor. in automatically preventing the retention or collection of moisture on any of the surfaces transmitting or absorbing heat, and in cormecca@ relating the volume-of vapor admitted to the cylinder, the structural characteristics affecting thermal conditions,`the thermal conditions, and the piston speed to Ainsure that the v'vapor in thecylinder shall be ina substanexpansion. l

37.v The method of obtaining Work from a vapor engine comprising a cylinder with a piston reciprocable therein, which 'consists tially saturated condition at the end of the in admitting vapor to the cylinder, in supplying heat from outside sources independently of the Working vapor to the Working vapor, in automatically preventing the retention or collection of moisture on the surfaces of the admission valve and admission passage, and in correlating the volume 'of vapor admitted to the cylinder, the structural characteristics affecting thermalconditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall be in a substantiallysaturated condition at the end of theexpansion.

38. The method of obtaining Work from a vapor engine comprising a cylinder With a piston reciprocable therein, which consists in admitting vapor to the cylinder, in supplying heat from outside sources independently of the Working vapor. to the working vapor, in automatically preventing the retention or`collection of moisture on the surfaces of or adjacent to the exhaust valve and passage, and ink correlating the volume of vapor admitted to the cylinder, the structural characteristicsafl'ecting thermal conditions, the thermal conditions, and the piston speed to insure that the vapor in the cylinder shall be in a substantially saturated condition at the end of the expansion.

39. The method of obtaining Work from a vapor motor which consists in admitting vapor to the motor, in controlling radiation and conduction from and to the vapor Workl ing in the motor, in supplyin heat from outside sources to the surface o the element movable by the action of the vapor, and in correlating the volume of vapor admitted to the motor, the resistance to the movement of said element, the structural'characteristics aecting thermal conditions, and' the thermal conditions in the motor to bring the vapor to, and maintain it in, a substantially saturated condition during a material and predetermined period of its passage through the motor.

40. The method of obtaining Work from a vapor motor which consists in admitting superheated vapor to the motor, in controlling radiation and conduction from and to the vapor Working in the motor, in supplying heat-from outside sources to the surface of the element movable by the action of the vapor, and in correlating the volume and.

quality of vapor admitted to the motor, the resistance to the movement of said element,

'tions in the motor to cause the vapor after it reaches the saturated condition to be maintained in such condition during a predetermined amount of expansion. Y

41. The method of obtaining Work from a vapor motor which consists in admitting vapor to the motor, in controlling radiation and conduction from and to thevapor Working -in the motor, in supplying heat from outside sources to the surface of the element movable by the action of the vapor, and in correlating the volume of vapor admitted to the motor, the speed of thesaid element, the structural characteristics ali'ecting thermal conditions, and the thermal conditions in the motor to bring the vapor to, and maintain it in, a substantially saturated condition during a material and predetermined period of its passage through the motor.

42. The method of obtaining Work from a vapor motor which consists in admitting superheated vapor to the motor, in controlling radiation and conduction from and to the vapor Working in the motor, in supplying heat from outside sources to the surface of the element movable by the action of the vapor, and in correlating the volume and quality of vapor admitted to the motor, the structural characteristics affecting thermal conditions, the other thermal conditions, and the speed of said element to cause the vapor after it reaches the saturated condition to be maintained in such condition d uring a predetermined amountof eXpan-' s1on. A

43. The method of obtaining Work from a vapor Inotor which consists in admitting vapor to the motor, in controlling radiation and conduction from and to the vapor Working in the motor, in supplying heat from outside sources to the surface of the element movable by the action of the vapor, and in correlating the Volume of vvapor admitted to the motor, the resistance to the movement of said element, the structural characteristics affecting thermal conditions, and the thermal conditions in the motor to regulate the amount of heat abstracted from the Working vapor. l l

44. The method of obtaining Work from a vapor engine comprising a cylinder With a vpiston reciprocable therein, which consists 

